edu.rice.cs.drjava.model.debug.jpda
Class EventHandlerThread

java.lang.Object
  java.lang.Thread
      edu.rice.cs.drjava.model.debug.jpda.EventHandlerThread

All Implemented Interfaces:

Runnable

public class EventHandlerThread
extends Thread

A thread that listens and responds to events from JPDA when the debugger has attached to another JVM.

Version:

$Id: EventHandlerThread.java 5442 2011-08-16 09:11:12Z rcartwright $

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

private boolean	_connected Whether this event handler is currently connected to the JPDA VirtualMachine.
private JPDADebugger	_debugger Debugger to which this class reports events.
private static Log	_log A log for recording messages in a file.
private com.sun.jdi.VirtualMachine	_vm JPDA reference to the VirtualMachine generating the events.

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

EventHandlerThread(JPDADebugger debugger, com.sun.jdi.VirtualMachine vm)
Creates a new EventHandlerThread to listen to events from the given debugger and virtual machine.

Method Summary

private void	_cleanUp(com.sun.jdi.event.Event e) Cleans up the state after the virtual machine being debugged dies or disconnects.
private void	_handleBreakpointEvent(com.sun.jdi.event.BreakpointEvent e) Responds to a breakpoint event.
private void	_handleClassPrepareEvent(com.sun.jdi.event.ClassPrepareEvent e) Responds when a class of interest has been prepared.
private void	_handleStepEvent(com.sun.jdi.event.StepEvent e) Responds to a step event.
private void	_handleThreadDeathEvent(com.sun.jdi.event.ThreadDeathEvent e) Reponds to a thread death event.
private void	_handleThreadStartEvent(com.sun.jdi.event.ThreadStartEvent e) Responds to a thread start event.
private void	_handleVMDeathEvent(com.sun.jdi.event.VMDeathEvent e) Responds if the virtual machine being debugged dies.
private void	_handleVMDisconnectEvent(com.sun.jdi.event.VMDisconnectEvent e) Responds if the virtual machine being debugged disconnects.
private boolean	_isSuspendedWithFrames(com.sun.jdi.ThreadReference thread) Returns whether the given thread is both suspended and has stack frames.
private void	_log(String message) Logs any unexpected behavior that occurs (but which should not cause DrJava to abort).
private void	_log(String message, Throwable t) Logs any unexpected behavior that occurs (but which should not cause DrJava to abort).
private void	handleDisconnectedException() Responds when a VMDisconnectedException occurs while dealing with another event.
private void	handleEvent(com.sun.jdi.event.Event e) Processes a given event from JPDA.
void	run() Continually consumes events from the VM's event queue until it is disconnected.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

_debugger

private final JPDADebugger _debugger

Debugger to which this class reports events.

_vm

private final com.sun.jdi.VirtualMachine _vm

JPDA reference to the VirtualMachine generating the events.

_connected

private volatile boolean _connected

Whether this event handler is currently connected to the JPDA VirtualMachine.

_log

private static final Log _log

A log for recording messages in a file.

Constructor Detail

EventHandlerThread

EventHandlerThread(JPDADebugger debugger,
                   com.sun.jdi.VirtualMachine vm)

Creates a new EventHandlerThread to listen to events from the given debugger and virtual machine. Calling this Thread's start() method causes it to begin listenting.

Parameters:

debugger - Debugger to which to report events

vm - JPDA reference to the VirtualMachine generating the events

Method Detail

_log

private void _log(String message)

Logs any unexpected behavior that occurs (but which should not cause DrJava to abort).

Parameters:

message - message to print to the log

_log

private void _log(String message,
                  Throwable t)

Logs any unexpected behavior that occurs (but which should not cause DrJava to abort).

Parameters:

message - message to print to the log

t - Exception or Error being logged

run

public void run()

Continually consumes events from the VM's event queue until it is disconnected.

Specified by:

run in interface Runnable

Overrides:

run in class Thread

handleEvent

private void handleEvent(com.sun.jdi.event.Event e)
                  throws DebugException

Processes a given event from JPDA. A visitor approach would be much better for this, but Sun's Event class doesn't have an appropriate visit() method.

Throws:

DebugException

_isSuspendedWithFrames

private boolean _isSuspendedWithFrames(com.sun.jdi.ThreadReference thread)
                                throws DebugException

Returns whether the given thread is both suspended and has stack frames.

Throws:

DebugException

_handleBreakpointEvent

private void _handleBreakpointEvent(com.sun.jdi.event.BreakpointEvent e)

Responds to a breakpoint event.

Parameters:

e - breakpoint event from JPDA

_handleStepEvent

private void _handleStepEvent(com.sun.jdi.event.StepEvent e)

Responds to a step event.

Parameters:

e - step event from JPDA

_handleClassPrepareEvent

private void _handleClassPrepareEvent(com.sun.jdi.event.ClassPrepareEvent e)

Responds when a class of interest has been prepared. Allows the debugger to set a pending breakpoint before any code in the class is executed.

Parameters:

e - class prepare event from JPDA

_handleThreadStartEvent

private void _handleThreadStartEvent(com.sun.jdi.event.ThreadStartEvent e)

Responds to a thread start event. Not run in event thread because threadStarted forces event thread execution.

Parameters:

e - thread start event from JPDA

_handleThreadDeathEvent

private void _handleThreadDeathEvent(com.sun.jdi.event.ThreadDeathEvent e)

Reponds to a thread death event.

Parameters:

e - thread death event from JPDA

_handleVMDeathEvent

private void _handleVMDeathEvent(com.sun.jdi.event.VMDeathEvent e)
                          throws DebugException

Responds if the virtual machine being debugged dies.

Parameters:

e - virtual machine death event from JPDA

Throws:

DebugException

_handleVMDisconnectEvent

private void _handleVMDisconnectEvent(com.sun.jdi.event.VMDisconnectEvent e)
                               throws DebugException

Responds if the virtual machine being debugged disconnects.

Parameters:

e - virtual machine disconnect event from JPDA

Throws:

DebugException

_cleanUp

private void _cleanUp(com.sun.jdi.event.Event e)
               throws DebugException

Cleans up the state after the virtual machine being debugged dies or disconnects.

Parameters:

e - JPDA event indicating the debugging session has ended

Throws:

DebugException

handleDisconnectedException

private void handleDisconnectedException()
                                  throws DebugException

Responds when a VMDisconnectedException occurs while dealing with another event. We need to flush the event queue, dealing only with exit events (VMDeath, VMDisconnect) so that we terminate correctly.

Throws:

DebugException